Arroyo Las Positas
| Arroyo Las Positas | |
|---|---|
 Arroyo Las Positas near its beginning, with Interstate 580 in the background.
| |
  Location of the mouth in California
| |
| Etymology | Spanish |
| Location | |
| Country | United States |
| State | California |
| Region | Alameda County |
| Cities | Livermore, Dublin |
| Physical characteristics | |
| Source | confluence |
| • location | north of Livermore |
| • coordinates | 37°42′20″N 121°45′18″W |
| • elevation | 482 ft (147 m) |
| Mouth | Arroyo Mocho |
• location |
north of Dublin |
• coordinates |
37°41′41″N 121°51′34″W |
• elevation |
348 ft (106 m) |
Arroyo Las Positas is a 7.4-mile-long (11.9 km) westward-flowing watercourse in Alameda County, California, which begins at the confluence of Arroyo Seco and Cayetano Creek north of Livermore, and empties into Arroyo Mocho in Dublin, California.